Pal 13: its moderately extended low density halo and its accretion history

A.E.PIATTI & J.G. FERNANDEZ-TRINCADO

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2020 vol. 635 p. 93 - 99

0004-6361

We present results on the basis of Dark Energy Camera Legacy Survey (DECaLS) DR8 astrometric and photometric data sets of the Milky Wayglobular cluster Pal 13. Because of its relative small size and mass,there has not been yet a general consensus about the existence of extra-tidalstructures around it. While some previous results claim for the absence of suchfeatures, others have shown that the cluster is under the effects of tidal stripping.From DECaLS g,r magnitudes of stars placed along the cluster Main Sequence in the colour-magnitude diagram --previously corrected by interstellar reddening--,we built the cluster stellar density map. The resulting density map showsnearly smooth contours around Pal 13 out to 1.6 times the mostrecent estimate of its Jacobi radius, derived by taking into account its variation along its orbital motion. This outcome favours the presence of stars escaping the cluster, a phenomenonfrequently seen in globular clusters that have crossed the Milky Way disca comparable large number of times. Particularly, the orbital higheccentricity and large inclination angle of this accreted globular clustercould have been responsible for the relatively large amountof cluster mass lost.